Infineon, the loss-making German chipmaker, has unveiled plans to raise as much as €735m ($1bn) from a rights issue to repay debt, after Apollo Global Management, the US private equity group, agreed to underwrite part of the issue.

The deal is an unusual move for Apollo and could end up with the New York-based group taking close to a 30 per cent stake in the chipmaker if its shareholders do not take up their rights.